Process of attaching heels to shoes



v- 9, 937. R. s. MEGATHLIN 2,09

PROCESS OF ATTACHING HEELS TO SHOES Filed Oct. 31, 1935 2 Sheets-Sheet l Wl/E/WUF Nov. 9, 1937. R s, MEGATHUN 2,098,349

PROCESS OF ATTACHING HEELS TO SHOES Filed Oct. 51, 1935 2 Sheets-Sheet 2 lation with the heel seat Patented Nov. 9, 1937 UNITED STATES 2,098,349 Y PROCESS OF ATTACHING HEELS To Sports Ralph S. Megathlin,

Wollaston. Marla, assignor to United Shoe Machinery Corporation, Paterson, N. J., a corporation of New Jersey Application 0mm e1, 1935, Serial No. 41,622

3 Claims. '(01. 12-141) This invention relates to shoemaking and is illustrated with reference to an improved method of attaching heels to shoes.

In preparing a shoe for the reception of a wood heel it is common practice to reduce the heel-seat portion of the sole of the shoe, suflicient stock being removed from the sole to insure that the rim of the attaching face of the heel will be forced into snug engagement with the overlasted counter portion of the shoe. Due to various irregularities or imperfections in'the construction of the heel seat of the shoe the overlasted counter portion of the shoe often has to be compressed considerably before the entire rim of the attaching face of the heel is forced against the shoe.

In order to insure that the heel shall be properly seated upon the shoe, it has been proposed to force the heel, the attaching face of which is coated with glue, under heavy molding pressure against the heel seat of the shoe, as disclosed in United States Letters Patent No. 1,747,216, granted February 18, 1930, upon an application filed in the name of Bertrand. While the heel is held in clamped relation with the shoe a temporary attaching screw is used to hold the heel securely in place in the desired reof the shoe. The shoe is then immediately removed from the machine and continues through the various finishing operations, during which time the temporary attaching screw prevents the heel seat of the shoe from springing back thereby insuring that the heel seat shall set in its molded conformation. The last upon which the shoe is mounted is generally removed from the shoe just prior to attaching the heel permanently to the shoe by inside nailing, the shoe being practically completed at this time. There is usually a lapse of several hours between the time the shoe is removed from the above machine and the time that the temporary screw is removed preliminary to removing the last from the shoe and it has been found that during this period the heel seat becomes permanently molded and therefore does not tend to return to its original shape when the screw is removed.

Sometimes use of the temporary attaching screw is eliminated and entire reliance is put upon the glue which is interposed between the heel and the heel seat, in order to secure the heel temporarily to the shoe until the last is removed and the heel is permanently attached by inside nailing. Under these conditions the heel is clamped against thedry heel seat and the pressure is maintained for as short a periodsgometimes as a few minutes. This may be done with the aid of a heel-attaching machine of the turret type, as illustrated, for example, in United States Letters Patent No. 1,376,539 granted May 3, 1921, on an application filed in the names of Isabelle Keane and John L. Preo. When shoes having Louis heels are operated upon in the above manner, covering flaps are usually applied to the breasts of the heels while the heels are clamped against the shoes.

It has been found that a large percentage of the heels which rely entirely upon the glue for the temporary bond between the heel and the heel seat become detached from their heel seats or at least become loose before they are nailed. Even though a heel does not become loose it may spring back from its conformation thereby causing the heel to shift its position upon the shoe. When the heel seat *of the shoe springs back as above described, a covering flap which may have been applied to a Louis heel attached to the shoe is likely to become wrinkled in the vicinity of the heel-breast line of the shoe due to the fact that it is moved with relation to the shoe during its permanent attachment to the shoe; and regardless of the type of heel, the heel-seat portion of the shoe will not be as solid as it should be.

With the above considerations in view, and in order that the heel-seat portion of the shoe may be eflectively and permanently compacted under molding pressure applied for as short a time as a few minutes through the heel, I propose to heat a mass of thermoplastic adhesive which is hard and rigid at ordinary temperatures and which is moldable when hot and will harden quickly, to soften the heel-seat portion of a sole in ,order to render the same moldable, to interpose a mass of the moldable adhesive between the heel seat of the shoe and the attaching face of a heel to be applied to the shoe in a quantity sufficient to fill voids included between the heel seat and the attached heel of the shoe, to force the attaching face of the heel against the heel seat under heavy pressure while the adhesive is hot in order to mold the heel seat and to cause the adhesive to spread sufficiently to fill said voids, and to maintain said heavy pressure for a short period to insure the cooling and hardening of the thermoplastic adhesive and the rigid securing oi! the heel to the shoe.

A thermoplastic adhesive which may be effectively used is disclosed in an application for United States Letters Patent Serial No. 47,284,

able shape to be included within molding pressure filed October 29, 1935, in the name of-Brandt. The thermoplastic adhesive may be applied to the heel seat or it may be applied to the attaching face of the heel, or to both. In order that the portion of the adhesive positioned adjacent to the heel shall not be suddenly chilled, the heel may be heated to a suitable temperature before the adhesive is applied thereto.

The invention will be better understood and appreciated after reading the following description in connection with the accompanying drawings, in which Fig. 1 is a. perspective view of the heel end of an inverted shoe mounted upon the last, the heel-seat-portion of the sole of the shoe having been prepared for' the reception of a. heel;

Fig. 2 shows the heel seat of the shoe illustrated in Fig. 1 in the process of being softened by a vapor bath preparatory to attaching the heel to the shoe;

Fig. 3 is a side view of the rear end of the shoe of Fig. 1 in the process of having a. heel attached thereto under heavy molding pressure;

Fig. 4 shows in perspective the heel seat bf the shoe after it has been molded under pressure of the heel, the heel and a portion of the heelbreast covering flap being shown in dotted lines;

Fig. 5 illustrates the heel end of the shoe shown in Fig. 1 in the process of being softened by dry heat;

Fig. 6 is a cross-sectional view of the heel seat of a shoe and a heel which is spaced from the shoe and has a quantity of thermoplastic adhesive applied to its attaching face; and

Fig. 7 is a transverse section taken through the rear end of the shoe and showing the heel of Fig. 6 after it has been forced with molding pressure against the heel seat of the shoe illustrated in Fig. 1.

In the manufacture of the shoe 24 a pair of heel-breast receiving shoulders 32 (Fig. 1) have been formed upon the sole 22 of the shoe and the heel-seat portion of the sole has been reduced, thereby providing a tongue 26 of suitthe attaching face of a wood heel 30. The tongue 26 is sometimes secured to the insole 34 of the shoe by a plurality of tacks 36. As above stated, because of certain irregularities in the construction of the heel end of the shoe, the overlasted counter portion 38 of the shoe usually comprises a somewhat rounded margin 40 and a heel-supporting surface including high and low areas 42, 44, respectively.

In attaching the heel to the shoe which is mounted upon a last 46 it is desirable to force the rim 48 of the attaching face 28 of the heel against the overlasted counter portion 38 of the shoe with suflicient force to form a shallow groove 50 (Fig. 4), the heel depressing the high areas 42 of the overlasted counter portion 38 in order that the same shall be engaged by substantially the entire rim 48 of the attaching face 28 of the heel 30. While the heel 30 is held with against the shoe the operator has an opportunity to pound the counter portion 52 (Fig. 7) of the shoe until the side and rear faces of the same merge smoothly with the side and rear faces of the heel.

In order to soften the heel seat so that it may be readily conformed to the shape of the heel and will have little if any tendency, as above described, to return to its original shape after the heel has been forced with molding pressure against the heel seat for a short period, there is provided a steam box 54 having an opening of suitable shape to receive the heel end of the shoe. Water which is supplied to a chamber 58 of the steam box 54 is heated by one or more V 1937 on an application filed in the name of Bazzoni. The heel, the attaching face 28 of which has been coated with glue, is then forced against the heel seat of the shoe under pressure of a back clamp 62 and a tread clamp 64 of the machine. Molding pressure of the heel against the heel seat is maintained for a short interval, for example a few minutes, which gives the operator an opportunity to pound the counter portion 52 of the shoe as above described.

As above stated, in Louis heel work it is customary to lay a covering flap 66 split from the sole, upon the breast of the heel while the heel is forced against the heel seat with molding pressure. When the heel seat is softened preparatory to attaching the heel temporarily to the shoe the overlasted counter portion 38 of the shoe is readily molded to a shape complemental to the margin of the attaching face of the heel and there is little, if any, tendency for the counter portion of the shoe to return to its original shape. It has been found that heels, which rely entirely upon the glue bond for their attachment to shoes, the heel seats of which have been softened and which have 'been subjected to heavy molding pressure for a short period, do not become loose between the temporary and the permanent heelattaching operations. Moreover, the heels do not shift with relation to the shoes at the time they are nailed to the shoes and the heel-breast flaps of the finished shoes are therefore free from wrinkles such as above described.

It has been proposed to attach heels to shoes by the use of thermoplastic adhesive HI (Fig. 6), as disclosed in detail in the above-mentioned application for United States Letters Patent Serial No. 47,284. Some thermoplastic adhesives tend to harden as soon as they engage the heel seat of the shoe. When this occurs excessive pressure is required to spread the adhesive upon the heel seat and it occasionally happens that the heel cannot be forced into its proper position upon the shoe without breaking the heel. With the above considerations in view it is proposed to heat the heel seat and, if desired, the heel, preparatory to interposing thermoplastic adhesive between the heel seat and the attaching face of the heel. The heel seat of the shoe may be effectively heated by positioning the same in an opening formed in a heat box 12 (Fig. 5) similar to the steam box 54 (Fig. 2) but supplying dry heat through an electric unit 14. The heel 20 may be conveniently heated in a suitable chamber (not shown) preparatory to attaching the same to the shoe.

When the operator is ready to attach the heel 30 to the shoe 24 he usually applies a substantial amount of thermoplastic adhesive" (Fig. 6) to the attaching face 28 of the heel and then forces the heel with molding pressure against the heel seat of the shoe by the use of the above-mentioned machine. The thermoplastic adhesive is of the proper consistency to insure that it shall set quite rapidly, thereby requiring that the heel be retained. under molding pressure against the shoe for only a few minutes. In order to increase the output of the machine the same may be of the turret type thereby permitting the clamped heels to be indexed while the thermoplastic adhesive is setting. When the heel seat is heated as above described it does not spring back to its original shape between the temporary the permanent heel-attaching operations. Moreover; the preheating of the heel seat of the shoe facilitates the proper spreading of the adhesive over the heel seat. Since the thermoplastic adhesive fills most of the voids included between the attaching face of the heel and the heel seat, there is a large area of bonded contact between the heel and the heel seat. Moreover, the thermoplastic cement which may be said to form part or the heel seat, provides a solid base to' which the heel may be securely attached. Various thermoplastic adhesives which may be effectively used are disclosed in the above-mentionedapplication for United States Letters Patent Serial No. 47,284,,

It will be understood that the heel seat may be reduced to various shapes .or may be entirely re:- moved in accordance with diiferent practices.

The amount of thermoplastic adhesives used will,v

therefore, depend largely upon the shape of the reduced heel seat and upon the shape of the attaching face of the heel.

Although the invention is illustrated with reference to water vapor and dry heat, it will be understood that I contemplate the use. of organic vapors and liquids in connection with the temporary attachment of heels to shoes.

Having described the invention. what I claim as new and desired to secure by Letters Patent of the United States is; v

1. The method of attaching heels to shoes which comprises, heating the heel seat of a shoe in order to render the same readily "moldable,

heating a heel which is to form a part of the shoe, applying a mass of thermoplastic adhesive to the attaching face of the heel, forcing the attaching face of the heel under heavy molding pressure against the heel seat of theshoe, and maintaining the molding pressure of the heel against the shoe in order to retain the heel seat in molded con- 2. The method of attaching heels to shoes.

which comprises, heating a mass of thermoplastic adhesive which is hard and rigid at ordinary temperatures and which is moldable when hot and will harden quickly, heating the heel-seat portion of a shoe to render the same moldable, interposing a mass of said moldable adhesive between the heel seat of the shoe and the attaching face of a heel to be applied to the shoe in a quantity sufiicient to fill voids-included between said heelseat and the attached heel of the shoe, forcing the attaching face of the heel against the heel seat under heavy pressure while the adhesive is hot in order to mold the heel seat and to cause the adhesive to spread sumciently to fill said voids, and maintaining said heavy pressure for a period to insure the cooling and hardening of the thermoplastic adhesive and the rigid securing of the heel to the shoe.

3. The method of attaching heels to shoes which comprises, heating a mass of thermoplastic adhesive which is hard and rigid at ordinary temperatures and which is moldable when hot and will harden quickly, heating the heel seat of a shoe to render the same moldable, heating the attaching face of a heel which is to form a part of the shoe, applying to said attaching face of the heel a quantity of thermoplastic adhesive sumcient to fill voids included between the heel seat of the shoe and the attached heel of the shoe, forcing the attaching face of the heel under heavy molding pressure against the heel seat of the shoe while the adhesiveis hot in order to mold the heel seat and to cause the. adhesive to spread sufliciently to fill said voids, and maintaining the moldingpressure of the heel against the shoe for a short period to insure the cooling and hardening of the thermoplastic and the rigid securing of the heel to the shoe.

RALPH S. MEGATHLIN. 

